package com.isoftstone.agiledev.manages;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;

public class RandomNumUtil {
	private ByteArrayInputStream image;//图像  
    private String str;//验证码  
    //验证码序列。
    private static final char[] randomSequence = new char[] { 'A', 'B', 'C', 'D', 'E', 'F', 'G',
        'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
        'U', 'V', 'W', 'X', 'Y', 'Z', '0','1', '2', '3', '4', '5', '6',
        '7','8', '9'};
 
   private RandomNumUtil(){  
        init();//初始化属性  
    }  
     
    public static RandomNumUtil Instance(){  
        return new RandomNumUtil();  
   }  
     
    public ByteArrayInputStream getImage(){  
       return this.image;  
   }  
     
    public String getString(){  
        return this.str;  
    }  
      
    private void init() {  
        //       在内存中创建图象  
        int width=85, height=20;  
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);  
        //       获取图形上下文  
        Graphics g = image.getGraphics();  
        //      生成随机类  
        Random random = new Random();  
        //       设定背景色  
        g.setColor(getRandColor(200,250));  
        g.fillRect(0, 0, width, height);
      //创建字体，字体的大小应该根据图片的高度来定。
        Font font = new Font("Times New Roman", Font.PLAIN, height-1);
        //设置字体。
        g.setFont(font);

        //随机产生155条干扰线，使图象中的认证码不易被其它程序探测到  
        g.setColor(getRandColor(160,200));  
        for (int i=0;i<155;i++ )  
        {  
         int x = random.nextInt(width);  
         int y = random.nextInt(height);  
                int xl = random.nextInt(12);  
                int yl = random.nextInt(12);  
         g.drawLine(x,y,x+xl,y+yl);  
        }  
        //取随机产生的认证码(6位数字)  
        String sRand="";  
        for (int i=0;i<4;i++ ){  
          int index = random.nextInt(36);
             String rand = String.valueOf(randomSequence[index]);
            sRand+=rand;  
            // 将认证码显示到图象中  
            g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));  
           
            g.drawString(rand,13*i+6,16);  
        }  
        this.str=sRand; 
        //       图象生效  
        g.dispose();  
        ByteArrayInputStream input=null;  
        ByteArrayOutputStream output = new ByteArrayOutputStream();  
        try{  
            ImageOutputStream imageOut = ImageIO.createImageOutputStream(output);  
            ImageIO.write(image, "JPEG", imageOut);  
            imageOut.close();  
            input = new ByteArrayInputStream(output.toByteArray());  
        }catch(Exception e){  
            System.out.println("验证码图片产生出现错误："+e.toString());  
        }  
          
        this.image=input; 
    }  
     
    /**
     * 随机产生颜色
     * @param fc
     * @param bc
     * @return
     */
    private Color getRandColor(int fc,int bc){  
        Random random = new Random();  
        if(fc>255) fc=255;  
        if(bc>255) bc=255;  
        int r=fc+random.nextInt(bc-fc);  
        int g=fc+random.nextInt(bc-fc);  
        int b=fc+random.nextInt(bc-fc);  
        return new Color(r,g,b);  
   }  
}
